Vivek control systems offers vivcon online ups systems which is based on high frequency pwm technology employing igb modules. These ups systems are of double conversion type and provide two level isolation between input and output. They have salient features like: fully isolated charger transformer for excellent noise immunity and to void shock hazards during battery maintenance; and vacuum impregnated crgo transformers for long life and low input losses Single/three phase full bridge scr controlled rectifier charger provides highly stables dc voltage with very little ripple content for charging the batteries. Batteries are charged using constant voltage with current limiting feature. The inverter is based on high frequency pwm technology employing igbt modules which provides advantages such as: crest factor of over three; pure sine wave with total harmonic distortion less than 3 per cent; excellent dynamic response; tight voltage regulation from no load to full load, ie, 1 per cent; low heat Generation; high efficiency typically >90 per cent, resulting in low power consumption; continuous duty; protection against over/under voltage, short circuit/over loading; compact/low noise; and convenient metering and indications for ease of operation.